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L.Ramamurthy
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Join Date: Jul 2009
Posts: 42

MOTOR FREQUENCY

01/18/2013 1:44 AM

DEAR TEAM,

I WANT TO RUN INDUCTION MOTOR FORM 0 TO 50HZ THROUGH A VARIABLE FREQUNCY DRIVE. WILL THERE BE ANY ISSUES?
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PWSlack
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United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
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#1

Re: MOTOR FREQUENCY

01/18/2013 3:27 AM

The first one is the unwarranted use of Caps Lock.

  • To what is the motor coupled?
  • What does its torque/speed characteristic look like?
  • Where on that curve is the motor going to need maximum cooling?
  • Is it worth over-sizing the motor and the drive to clear the peak of that curve with capacity to spare?
  • What are the hazardous area implications?
  • How far is the distance along the cable from the drive to the motor?
  • Is there a competent person available to select the motor/driven component/variable frequency drive correctly?
  • Is there a competent person available to programme the drive correctly?
  • Is the supply adequately sized for the job?
  • Etc., etc.
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L.Ramamurthy
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Join Date: Jul 2009
Posts: 42
#2
In reply to #1

Re: MOTOR FREQUENCY

01/18/2013 3:33 AM

THIS IS FOR A SCREW AIR COMPRESSOR
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PWSlack
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#3
In reply to #2

Re: MOTOR FREQUENCY

01/18/2013 3:43 AM

So what?

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lyn
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Join Date: Oct 2008
Posts: 42355
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#4

Re: MOTOR FREQUENCY

01/18/2013 4:55 AM

YES. IF YOU WANT THE SHAFT TO GO ROUND N ROUND.
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Tornado
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Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21017
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#5

Re: MOTOR FREQUENCY

01/18/2013 9:05 AM

A screw compressor would be considered a constant-torque load. Select the type of VFD accordingly. Also check whether the lubrication system will function properly at less than full speed.

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JRaef
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United States - Member - New Member Engineering Fields - Power Engineering - New Member

Join Date: Sep 2006
Location: California, USA, where the Godless live next door to God.
Posts: 4665
Good Answers: 804
#6

Re: MOTOR FREQUENCY

01/18/2013 1:36 PM

Start with Why!

Not every application can benefit from having a VFD applied to it, despite the marketing materials that come from VFD mfrs.

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Anonymous Poster #1
#7

Re: MOTOR FREQUENCY

01/18/2013 3:49 PM

BUT IF I TOUCH THE "CAPS LOCK" KEY, HOW WILL I GET MY CAPS UNLOCKED?
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JRaef
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#8
In reply to #7

Re: MOTOR FREQUENCY

01/19/2013 12:36 PM

Step AWAY from the computer!

The International Cabal of Users Technical Oversight Ombudsmen (ICUTOO) has determined that if you cannot figure out how to unlock your Caps Lock feature, you are likely to do something that will harm the internet.

Cease and desist immediately!

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L.Ramamurthy
Associate

Join Date: Jul 2009
Posts: 42
#9
In reply to #8

Re: MOTOR FREQUENCY

01/20/2013 12:01 AM

thanks for your inputs. i was able to succefully commisionin on 20hz
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Users who posted comments:

Anonymous Poster (1); JRaef (2); L.Ramamurthy (2); lyn (1); PWSlack (2); Tornado (1)

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